How to set lines mesh vertices positions

[mwpowellhtx]

Hello,

I want to update the vertices of a lines mesh after it has been created. On a sphere, by contrast, I can do so fairly simply:

mySphere.position.x = myX;
mySphere.position.z = myZ;

But there does not appear to be anything like that for lines mesh:

// myLines.positions is undefined ????
myLines.positions[0].x = myPositions[0].x;
myLines.positions[0].z = myPositions[0].z;
myLines.positions[1].x = myPositions[1].x;
myLines.positions[1].z = myPositions[1].z;
// myLines._positions is null ????
myLines._positions[0].x = myPositions[0].x;
myLines._positions[0].z = myPositions[0].z;
myLines._positions[1].x = myPositions[1].x;
myLines._positions[1].z = myPositions[1].z;

Is the only way to make the mesh updatable and send a new array of points in via the options? Doable, but it's more of a pain, IMO.

Insight appreciated. Thanks!

[mwpowellhtx]

The nearest thing I can see potentially being able to do this is, line._geometry.setIndices, but with the underscore, I am hesitant to accept that without knowing a bit more about the context.

[GameMonetize]

Hum...I think there is a misunderstanding here.

This does not change the geometry but just the position of the mesh:

mySphere.position.x = myX;
mySphere.position.z = myZ;

To change the inner vertex buffer, you have to use mesh.getVerticesData.

This article uses it extensively http://doc.babylonjs.com/tutorials/How_to_Merge_Meshes

And you can find tons of samples in the PG:http://doc.babylonjs.com/playground?q=getVerticesData

 

[adam]

https://www.google.com/search?q=update+linesmesh+babylonjs&oq=update+linesmesh+babylonjs&aqs=chrome..69i57.17070j0j4&sourceid=chrome&ie=UTF-8

[mwpowellhtx]

27 minutes ago, Deltakosh said:

Hum...I think there is a misunderstanding here.

This does not change the geometry but just the position of the mesh:

mySphere.position.x = myX;
mySphere.position.z = myZ;

To change the inner vertex buffer, you have to use mesh.getVerticesData.

This article uses it extensively http://doc.babylonjs.com/tutorials/How_to_Merge_Meshes

And you can find tons of samples in the PG:http://doc.babylonjs.com/playground?q=getVerticesData

 

Perhaps a misunderstanding of the vocabulary.

In the case of the spheres, I want to reposition them; that's exactly what I need.

In the case of the lines, I expect to add vertices to it, or remove vertices from it; at minimum, wholesale replace the vertices, but avoid replacing the mesh itself if I can help it.

[GameMonetize]

Ok I get your point

So getVerticesData and updateVerticesData are the way to go

[mwpowellhtx]

@Deltakosh Alright, so it sounds like a stupid question, but when I want to update the BABYLON.Vector3 points in the lines mesh, which Kind do I use?

[mwpowellhtx]

If I call BABYLON.MeshBuilder.CreateLines(...) having set the { updatable: true } option, I should be able to call CreateLines(...) with { points: [...], instance: l }. However, I get several warnings piling up, "WebGL: INVALID_VALUE: bufferSubData: buffer overflow", and when I interact with the lines to set their visibility, I get an exception: "Uncaught TypeError: Cannot read property 'boundingSphere' of undefined".

[adam]

http://www.babylonjs-playground.com/#24PQRQ

[jerome]

maybe : http://doc.babylonjs.com/tutorials/How_to_dynamically_morph_a_mesh#lines-and-dashedlines